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HELP Tubelab sse beginner problem

This is my first amplifier project and it's one of the most cool thing I've ever built. Unfortunately there is no sound from the left channel. All tubes lights up and seems ok in the dark.

Component list:
PT: Hammond 374BX
OT: Hammond 1628SEA
Choke: Hammond 193H
Auxilliary cap: Temco 100 uf
Tubes: 12AT7 Electro Harmonix, Sovtek 5AR4, EL34 Electro Harmonix

I took some voltage measures:
B+: 450 vdc
R17: 32
R27: 33
R10: 0
R20 0

I thought the problem was my potentiometer so I removed it: no change. I've redone all soldering on both side. I took basic triode wiring for my amplifier. D3,D4 TR1 are jumpered. The problem seems in the preamp section... I'm facing a wall, any advice ?
 

Steady7

Member
2015-02-06 10:10 pm
This is my first amplifier project and it's one of the most cool thing I've ever built. Unfortunately there is no sound from the left channel. All tubes lights up and seems ok in the dark.

Component list:
PT: Hammond 374BX
OT: Hammond 1628SEA
Choke: Hammond 193H
Auxilliary cap: Temco 100 uf
Tubes: 12AT7 Electro Harmonix, Sovtek 5AR4, EL34 Electro Harmonix

I took some voltage measures:
B+: 450 vdc
R17: 32
R27: 33
R10: 0
R20 0

I thought the problem was my potentiometer so I removed it: no change. I've redone all soldering on both side. I took basic triode wiring for my amplifier. D3,D4 TR1 are jumpered. The problem seems in the preamp section... I'm facing a wall, any advice ?

Go ahead a upload some pictures of your board. This will be very helpful for us to maybe guide you in the right direction.
 
Here's pictures of my board. I'm a beginner so please constructives advices or comments.
 

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Steady7

Member
2015-02-06 10:10 pm
Here's pictures of my board. I'm a beginner so please constructives advices or comments.

The best advice I can give you right now would be to go back and check your soldering on all your resistors especially your coupling caps, looks like a majority of them may need a bit more solder to make a solid connection. You want them to look like a little "ant hill"

If you have a multimeter I would take that and ohm out all your resistors going from solder pad to solder pad across the resistor to make sure you have continuity across the resistors, do not touch the leads of the resistor with the meter leads just solder pads. If meter reads OL or nothing there is your open.

I'm sure someone will chime in about what else to checkout for not having sound in the left channel.
 
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Steady7

Member
2015-02-06 10:10 pm
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